5-氯水杨醛缩2,4-二羟基苯酰肼的抗菌抗氧化活性研究

目的考察5-氯水杨醛缩2,4-二羟基苯酰肼对金黄色葡萄球菌的抗菌活性及体外抗氧化活性。方法采用试管法和平板法测定其对金黄色葡萄球菌最小抑菌浓度(MIC)、最小杀菌浓度(MBC),绘制杀菌曲线,并通过扫描电镜研究其作用机制,采用DPPH法测定抗氧化活性。结果该化合物对金黄色葡萄球菌的MIC为2.5 mg/m L,MBC为5 mg/m L。杀菌曲线结果表明该化合物对金黄色葡萄球菌的杀菌作用表现出明显的浓度依赖性。扫描电镜结果表明该化合物的作用机制可能与破坏菌体细胞壁、改变其通透性有关。同时该化合物具有较强的清除自由基的能力。结论 5-氯水杨醛缩2,4-二羟基苯酰肼具有显著的抗金黄色葡萄球菌作用,同时具有较好的体外抗氧化活性。     

一种植物生长激素-N'-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼的合成、晶体结构和抗菌活性

目的:合成并表征一种属于植物生长激素的席夫碱类化合物.方法:由5-硝基水杨醛和3,5-二羟基苯甲酰肼在甲醇溶液中反应得到N′-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼.结果:用单晶X-射线衍射法测得其结构并表征,同时通过抗菌实验证明其在一定浓度下具有明显的抗菌活性.结论:这种席夫碱类化合物在某种程度上具有明显的抗菌活性.     

紫穗槐种子提取物的抑菌活性研究

目的研究紫穗槐种子提取物的抑菌活性。方法将紫穗槐种子乙醇提取物分别通过石油醚、乙酸乙酯和正丁醇萃取,选择金黄色葡萄球菌和肺炎克雷伯杆菌为供试菌,采用试管二倍稀释法测定紫穗槐种子提取物的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）,涂布平板法绘制杀菌曲线,电镜下观察药物对细菌超微结构的影响。结果紫穗槐种子提取物经乙酸乙酯萃取后对供试菌抑制作用较强,其中对金黄色葡萄球菌的MIC和MBC分别为2．5、5．0mg／mL;对肺炎克雷伯杆菌的MIC和MBC分别为5．0、10．0mg／mL;杀菌曲线结果表明,药物对供试菌的抑制作用存在浓度和时间依赖性;电镜结果说明,药物的作用可能与破坏菌体细胞壁、改变细胞膜通透性有关。结论紫穗槐种子提取物具有显著的抗菌活性。     

蓝莓提取物对产超广谱β-内酰胺酶肺炎克雷伯菌的抑菌活性

【背景】随着细菌耐药性的增强,产超广谱β-内酰胺酶肺炎克雷伯菌的出现严重危害食品安全和人体健康。蓝莓中含有丰富的多酚和花青素,是天然抗菌材料的优选。【目的】分析蓝莓提取物对3株产超广谱β-内酰胺酶肺炎克雷伯菌的抑制活性及作用机制,并以牛乳为样品检测食品基质对蓝莓提取物抑菌活性的影响。【方法】利用甲醇制备巴尔德温和黑珍珠蓝莓提取物并检测提取物中总酚和花青素含量,利用纸片扩散法检测肺炎克雷伯菌的耐药性,利用最小抑菌浓度(minimum inhibitory concentration,MIC)、最小杀菌浓度(minimum bactericidal concentration,MBC)和生长曲线研究蓝莓提取物的抗菌活性,通过共聚焦激光扫描显微镜观察蓝莓提取物对细胞膜完整性的影响,并检测其在牛乳中的抑菌活性。【结果】巴尔德温和黑珍珠蓝莓提取物中的总酚含量分别为2.3 mg/g和3.5 mg/g,花青素含量分别为67.5 mg/100 g和92.5 mg/100 g。两种蓝莓提取物对肺炎克雷伯菌KP106、KP305和KP408的MIC均为25mg/mL,MBC均为50mg/mL。生长曲线表明...     

胶体纳米银对产超广谱β-内酰胺酶肺炎克雷伯菌的抑制作用

目的探讨胶体纳米银对产超广谱β-内酰胺酶(ESBLs)肺炎克雷伯菌的抑制作用。方法以产ESBLs肺炎克雷伯菌为研究对象,采用涂布法检测杀菌作用,肉汤微量稀释法测量最低抑菌浓度(MIC),电镜法观察胶体纳米银对产ESBLs肺炎克雷伯菌的作用机理。结果≥0.5μg/mL的胶体纳米银对产ESBLs的肺炎克雷伯菌具有100%杀菌作用;≥0.05μg/mL的胶体纳米银对产ESBLs的肺炎克雷伯菌也具有明显的杀菌作用;5μg/mL胶体纳米银对产ESBLs肺炎克雷伯菌5、15、30和60 min均有明显的杀菌作用;胶体纳米银对产ESBLs肺炎克雷伯菌的MIC为3.125μg/mL;不同因素对胶体纳米银的杀菌作用,蛋白因素影响显著(P0.05);胶体纳米银对产ESBLs肺炎克雷伯菌的形态学有明显影响。结论胶体纳米银对产ESBLs肺炎克雷伯菌具有明显的抑制作用,这些结果将为胶体纳米银的临床应用提供了实验依据。     

一个戊二烯酮化合物的合成及其杀菌抗癌活性

目的:合成戊二烯酮类化合物(1E,4E)-1,5-二(2-羟基苯基)-1 ,4-戊二烯-3-酮,并进行杀菌和抗肿瘤活性测定.方法:水杨醛和丙酮反 应得到目标产物;采用生长速率法和MTT比色法分别测定了该化合物的杀菌抗癌活性.结果:目标物结构经元素分析、红外光谱、核磁共振氢谱确证;该化合物在500 μg/mL浓度下对小麦赤霉病原菌、辣椒枯萎病原菌、苹果腐烂病原菌的抑制率分别为73.0% ±3.3%、70.4%±1.5%、79.2%±2.1%;在5.0ìmol/L下对PC-3细胞的72h的体外抑制率为71 .4%±2.7%.结论:该化合物有较好的杀菌抗癌活性,可以以它为先导进行结构优化,以期设计、合成出高效、选择性好的同类化合物.     

甘草提取物对四种牙周常见致病菌的抑菌作用

目的体外评价甘草提取物对牙龈卟啉单胞菌、中间普氏菌、具核梭杆菌和伴放线放线杆菌四种牙周常见致病菌的抑制效果。方法以牙龈卟啉单胞菌、中间普氏菌、具核梭杆菌和伴放线放线杆菌四种牙周常见致病菌作为供试菌,采用液体稀释法,考察甘草提取物对这四种细菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC);并采用不同浓度的甘草提取物溶液,绘制甘草提取物对四种牙周致病菌的时间-杀菌曲线。结果甘草提取物对牙龈卟啉单胞菌、中间普氏菌、具核梭杆菌和伴放线放线杆菌的MIC值分别为1.50、1.50、0.75和1.50mg/mL,MBC值分别为6、3、3和3mg/mL。当甘草提取物达到对四种细菌的MBC值时,对于牙龈卟啉单胞菌、中间普氏菌、伴放线放线杆菌可在2h后可达到杀菌效果,对于具核梭杆菌可在4h后达到杀菌效果。结论甘草提取物对以上四种牙周常见致病菌具有良好的抑菌及杀菌作用。     

华泽兰根的化学成分及其体外抑菌活性研究北大核心CSCD

利用硅胶、Sephadex LH-20、HPLC等各种色谱分离技术,从华泽兰根的乙醇提取物中分离得到9个化合物,通过理化性质和NMR波谱数据对它们进行了结构鉴定,分别为:达玛二烯醇乙酸酯(1)、(2R,3S)-5-乙酰基-6-羟基-2-异丙烯基-3-乙氧基苯并二氢呋喃(2)、豆甾醇(3)、邻苯二甲酸二丁酯(4)、12,13-dihydroxyeuparin(5)、5-乙酰-6-羟基-2-异丙烯基苯并呋喃(6)、2,5-二乙酰基-6-羟基苯并呋喃(7)、ruscodibenzofuran(8)、2-乙酰-5-(1-炔丙基)-噻吩-3-O-β-D-吡喃葡萄糖苷(9)。化合物1、2、4和8为首次从该种植物中分离得到,其中2、4和8为首次从该属植物中分离得到。采用牛津杯法评价部分化合物对5种病原菌的抑菌活性,并用肉汤稀释法测定各自的MIC值,结果显示,测试化合物对5种菌具有不同程度的抑菌活性,其中,1、6和8对肺炎克雷伯菌有较强抑菌活性,MIC值分别为0.98、0.98μg/m L和0.49μg/m L,化合物7对大肠埃希菌显示较强抑菌活性(MIC≤3.91μg/m L),化合物1、2、6和7对铜绿假单胞菌有较强抑菌活性,MIC值均为7.81μg/m L,可见化合物1及苯并呋喃类化合物2、6、7、8为华泽兰根主要抑菌活性成分。     

液体接触法与气相接触法对单离香料抗菌作用的影响

通过测定单离香料在液体接触、气相接触2种方法对7种供试菌的最小抑菌浓度(MIC值)和最小杀菌浓度(MBC值),用重复测量方差分析、秩和检验探讨不同接触方式对单离香料抗菌效果的影响。结果表明液体接触法中百里香酚、水杨醛对供试菌MIC值均为0.125μL/mL,肉桂醛、柠檬醛MIC值范围为0.25～0.5μL/mL,丁香酚、芳樟醇的MIC值范围为0.25～2.0μL/mL。气相法试验中水杨醛、百里香酚对供试菌的MIC值均为0.125μL/mL,芳樟醇MIC值范围为0.25～1.0μL/mL,肉桂醛、柠檬醛MIC值范围为0.5～1.0μL/mL,而丁香酚在供试范围(8μL/mL)内仅对副溶血性弧菌有抗菌作用。用MIC值重复测量方差分析,水杨醛、百里香酚在液体接触法与气相接触法存在显著性差异,P0.05,液体接触法明显优于气相法;从MBC值分析,芳樟醇、水杨醛、丁香酚在2种接触方式中存在显著性差异,P0.05,其中芳樟醇、水杨醛的液体接触法明显优于气相法,而丁香酚则相反。单离香料与菌体的作用方式会影响其抗菌效果,因此利用单离香料的抗菌性能开发新型抗菌剂,需全面评估其抗菌性能。     

华泽兰根的化学成分及其体外抑菌活性研究

利用硅胶、Sephadex LH-20、HPLC等各种色谱分离技术,从华泽兰根的乙醇提取物中分离得到9个化合物,通过理化性质和NMR波谱数据对它们进行了结构鉴定,分别为:达玛二烯醇乙酸酯(1)、(2R,3S)-5-乙酰基-6-羟基-2-异丙烯基-3-乙氧基苯并二氢呋喃(2)、豆甾醇(3)、邻苯二甲酸二丁酯(4)、12,13-dihydroxyeuparin(5)、5-乙酰-6-羟基-2-异丙烯基苯并呋喃(6)、2,5-二乙酰基-6-羟基苯并呋喃(7)、ruscodibenzofuran(8)、2-乙酰-5-(1-炔丙基)-噻吩-3-O-β-D-吡喃葡萄糖苷(9)。化合物1、2、4和8为首次从该种植物中分离得到,其中2、4和8为首次从该属植物中分离得到。采用牛津杯法评价部分化合物对5种病原菌的抑菌活性,并用肉汤稀释法测定各自的MIC值,结果显示,测试化合物对5种菌具有不同程度的抑菌活性,其中,1、6和8对肺炎克雷伯菌有较强抑菌活性,MIC值分别为0.98、0.98μg/m L和0.49μg/m L,化合物7对大肠埃希菌显示较强抑菌活性(MIC≤3.91μg/m L),化合物1、2、6和7对铜绿假单胞菌有较强抑菌活性,MIC值均为7.81μg/m L,可见化合物1及苯并呋喃类化合物2、6、7、8为华泽兰根主要抑菌活性成分。     

Synthesis and biological evolution of hydrazones derived from 4-(trifluoromethyl)benzohydrazide

Reflecting the known biological activity of isoniazid-based hydrazones, seventeen hydrazones of 4-(trifluoromethyl)benzohydrazide as their bioisosters were synthesized from various benzaldehydes and aliphatic ketones. The compounds were screened for their in vitro activity against Mycobacterium tuberculosis, nontuberculous mycobacteria (M. avium, M. kansasii), bacterial and fungal strains. The most antimicrobial potent derivatives were also investigated for their cytostatic and cytotoxic properties against three cell lines. Camphor-based molecule, 4-(trifluoromethyl)-N′-(1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)benzohydrazide, exhibited the highest and selective inhibition of M. tuberculosis with the minimum inhibitory concentration (MIC) of 4?µM, while N′-(4-chlorobenzylidene)-4-(trifluoromethyl)benzohydrazide was found to be superior against M. kansasii (MIC?=?16?µM). N′-(5-Chloro-2-hydroxybenzylidene)-4-(trifluoromethyl)benzohydrazide showed the lowest MIC values for gram-positive bacteria including methicillin-resistant Staphylococcus aureus as well as against two fungal strains of Candida glabrata and Trichophyton mentagrophytes within the range of ≤0.49–3.9?µM. The convenient substitution of benzylidene moiety at the position 4 or the presence of 5-chloro-2-hydroxybenzylidene scaffold concomitantly with a sufficient lipophilicity are essential for the noticeable antimicrobial activity. This 5-chlorosalicylidene derivative avoided any cytotoxicity on two mammalian cell cultures (HepG2, BMMΦ) up to the concentration of 100?µM, but it affected the growth of MonoMac6 cells.     

2008-2012年484株肺炎克雷伯菌耐药性分析及耐药机制的初步研究

目的回顾性分析近五年来医院住院及门诊病原菌感染患者中肺炎克雷伯菌的分离趋势,探讨其对常规抗菌药物的耐药性变迁和相关耐药机制。方法采用法国梅里埃公司的Vitek-2 Compact全自动微生物分析仪进行细菌鉴定及药敏试验,部分菌株采用微量生化管鉴定,部分药敏试验采用琼脂扩散法（KB）,药敏结果判读按照美国临床和实验室标准化协会（CLSI）制定的标准判读,纸片法表型确证试验检测超广谱β-内酰胺酶（ESBLs）,改良Hodge试验检测碳青霉烯酶表型,EDTA双纸片法检测金属酶表型。结果五年间484株肺炎克雷伯菌部分药物耐药率正逐年上升,其常见药物平均耐药率如下：阿米卡星（3.0%）,复方新诺明（31.1%）,头孢三嗪（14.5%）,环丙沙星（18.7%）,氯霉素（21.6%）,特治星（6.3%）,头孢他啶（22.0%）,头孢噻肟（23.6%）,舒普深（4.2%）,呋喃妥英（26.9%）,美罗培南（2.1%）,ESBLs阳性99株（20.4%）,改良Hodge试验检测碳青霉烯酶表型阳性5株,EDTA双纸片法检测金属酶表型阳性2株。结论部分药物耐药率逐年上升的有复方新诺明、环丙沙星、头孢他啶、头孢噻肟;耐药率较低的有美罗培南、阿米卡星、舒普深、特治星、头孢三嗪。应加强细菌耐药性监测,以及耐碳青霉烯酶筛查试验,为临床提供用药参考。     

氟喹诺酮类药物体外诱导肺炎克雷伯菌耐药后GyrA和ParC的变异

目的了解3种氟喹诺酮类（FQS）体外诱导肺炎克雷伯菌（Klebsiella pneumoniae,Kpn）耐药性的差异,研究肺炎克雷伯菌DNA旋转酶A亚单位（GyrA）和拓扑异构酶ⅣC亚基（ParC）的变异与其耐喹诺酮类药物的关系。方法采用环丙沙星（CW）、左氧氟沙星（LEX）和加替沙星（GAT）对从临床分离8株Kpn进行体外分步诱导,采用琼脂平板二倍稀释法测定CIP、LVF及GAT对Kpn诱导前、后的最低抑菌浓度（MIC）,并对诱导成功的17株Kpn的GyrA的基因（gyrA）和ParC的基因（parC）进行PCR扩增,选取其中8株KpnDNA测序并进行序列分析比较。结果8株耐FQS菌株都存在GyrA变异,同FQS耐药性相关的变异有Ser83（TCC）→Phe（TTC）、Ile（ATC）和Tyr（TAC）,Asp87（GAC）→Ala（GCC）、ma（GCC）和Glu（GAA）,5株Kpn同时存在ParC的变异：丝氨酸Ser80（AGC）→Ile（ATC）。结论本研究体外实验证实了Kpn可在长期低剂量的接触抗菌药物后形成耐药菌株。在高度耐FQS的Kpn中同时存在GyrA和ParC变异。     

土茯苓提取物抗细菌活性的研究

通过测定土茯苓提取物对革兰氏阳性菌和革兰氏阴性菌的抑菌活性,来更全面的评价和综合利用土茯苓资源,实验结果表明土苓955乙醇和乙酸乙酯的提取物抑菌范围广,服抑菌活性强,这两种提取物的MIC和MBC值显示了土茯苓作为抗细菌资源的可利用价值。     

Synthesis and in vitro microbiological evaluation of novel diethyl 6,6'-(1,4-phenylene)bis(4-aryl-2-oxo-cyclohex-3-enecarboxylates)

Novel bis cyclohexenone ester derivatives 14-19 were synthesized and characterized by their spectral data. In vitro microbiological evaluations were carried out for all the novel compounds 14-19 against clinically isolated bacterial and fungal strains. Compounds 15, 16, 18 against Staphylococcus aureus, 14, 15 against β-Haemolytic streptococcus, 15, 19 against Micrococcus luteus, 17, 18 against Salmonella typhii, 14, 17 against Shigella flexneri, 15 against Escherichia coli, 16 against Pseudomonas aeruginosa, 15, 18, 19 against Klebsiella pneumonia exhibited potent antibacterial activity at an minimum inhibitory concentration (MIC) value of 6.25 μg/ml, whereas compound 16 against Aspergillus flavus, 17 against A. niger, 16, 18 against Mucor indicus, 15, 17-19 against Microsporum gypseum revealed excellent antifungal activity at an MIC value of 6.25 μg/ml.     

Novel 2-(2-(4-aryloxybenzylidene) hydrazinyl)benzothiazole derivatives as anti-tubercular agents

A series of structurally novel, substituted 2-(2-(4-aryloxybenzylidene) hydrazinyl)benzothiazole derivatives incorporating 2-hydrazinyl benzothiazole and 4-(aryloxy)benzaldehyde were designed and synthesized using molecular hybridization approach. All the synthesized compounds exhibited promising activity (MIC 1.5-29.00μg/ml) against Mycobacteriumtuberculosis H37Rv strains of using REMA. Five of the evaluated compounds exhibit MIC <3.0μg/ml. Compound (E)-6-chloro-2-(2-(4-(2,4-dichlorophenoxy)benzylidene)hydrazinyl) benzothiazole showed MIC of 1.5μg/ml. Thus, this compound could act as a potential lead for further development of new anti-tubercular drugs.     

Inhibition of Klebsiella pneumoniae ATCC 13883 cells by hexane extract of Halimeda discoidea (Decaisne) and the identification of its potential bioactive compounds

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 log10, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GCMS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.     

Synthesis, characterization and in vitro antimicrobial evaluation of new compounds incorporating oxindole nucleus

New compounds incorporating with the oxindole nucleus were synthesized via the reaction of substituted isatins [5-methyl-, 5-chloro- and 1-hydroxymethyl isatins] with different nucleophiles. The structures of the newly compounds were elucidated on the basis of FTIR, (1)H NMR, (13)CMR spectral data, GC/MS and chemical analysis. Investigation of antimicrobial activity of the new compounds was evaluated using broth dilution technique in terms of minimal inhibitory concentration (MIC) count against four pathogenic bacteria and two pathogenic fungi. Most of the new compounds are significantly active against bacteria and fungi. MIC showed that compound (4a) possesses higher effect on Gram-positive bacteria Bacillus cereus than the selected antibacterial agent sulphamethoxazole, whereas compound (11c) possesses more activity against Gram-negative bacteria Shigella dysenterie.